#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
class sum
{
public:
    sum()
    {
        ret += _i;
        _i += 1;
    }
    static int GetSumRet()
    {
        return ret;
    }

private:
    static int ret;
    static int _i;
};

int sum::ret = 0;
int sum::_i = 1;

class Solution {
public:

    int Sum_Solution(int n) {
        sum a[n];
        return sum::GetSumRet();
    }

};